Apologies if this subject has been done to death. Please bear with me.

I'm considering importing an incredibly low mileage (about 10,000 miles) 1999 XJR V8 Supercharged over from Japan and would want to turn it into a bit of a project to boost power and handling, but without losing too much of the ability to 'waft' effortlessly when being sensible and just cruising.

Also, an exhaust that brings out the snarl of the V8, without constant droning on long runs, would be great.

Ideally from experience, what would your recommendations be?

And would sort of power increases and handling benefits could I expect to see?

If I had to put a budget just on improvements I'd say about 5k to spend initially. No doubt more over time.

 

That's an amazing find (personally I'd just enjoy it as is, but it's your Jag have at it), ...you'll be dealing with the AJ26 motor which has Nikasil lined cylinders. There is not a ton you can do with the Eaton SC, nor head work (coat the rotors at most or replace the Eaton with a KB from member https://www.jaguarforums.com/forum/market/287736 ). You can advance the Eaton boost range by changing either or both upper/lower pulleys (check Powerhouse's site) and there's a couple threads on here of those who have done it. That $5k would just get you the SC BTW....so if you want to stay mild, think of the pulleys.

Site member Avos is renowned for his KB kits, do a search Avos supercharger and you'll get a lot of threads.

Here's a thread from a fellow Brit that may interest you, ...https://www.jaguarforums.com/forum/x...-build-259817/

 

@Highhorse that's great advice, thank you! I've contact JagSTR2004 about the supercharger mods, and loving that thread by PandaSpeedShop

 

This forum has all the info you need - 'upgrades supercharger' search..... I would start with the upper and lower pullies and belt, a quality aftermarket aluminium intercooler rad, silicone hoses and an upgraded Bosch intercooler pump. It doesn't give more dyno output, but shifts the torque curve in earlier.
There maybe decayed bushes on the subframes so have all of them changed, 25 years.
R1 stuff is nice to add if you can find it at reasonable prices (BBS/Brembo package)
Exhausts, others have better advice than I can give - there are options but research to avoid the dreaded drone.